WiMAX
 

Johny Johny !

Yes, Papa !

Shall we go to a movie today?

Sorry Dad, I have to write an article on WiMAX for our school magazine.

Very Good ! What you know about WiMAX?

Absolutely Nothing. I am going to learn from you only.    WiMAX stands for what, Dad?

WiMAX stands for Worldwide Interoperability for Microwave Access.

What is the meaning of Interoperability?

Interoperability means fully standardised and the  product  is compatible and able to work in harmony with other vendors equipments.

What is the meaning of Microwave?

30 MHz to 300 MHz is VHF (Very High Freq) ...( eg. FM Radios and VHF Television channels)

300 MHz to 3 GHz is UHF (Ultra High Freq)..... (eg. UHF TV Chnls,Microwave Oven and blue tooth,wi-fi,wimax)

3 GHz to 30 Ghz  is  SHF (Super High Frequency).....(eg. wi-fi,wimax)

30 GHz to 300 GHz is EHF (Extremely High Frequency)

AS per old standards ,300Mhz to 300 GHz (UHF, SHF and EHF) is  called as Microwave frequency.

As per some new standards, 1GHz to 1000GHz is called as Microwave frequency.

 

What is the main difference between wi-fi and wimax?

Main thing is coverage distance. wi-fi can cover a distance of about 150 m, but wimax can cover about 150KM. Have look at this image:

 

Who can use this WiMAX?

WiMAX  is mainly for last mile broadband access. It can be used for  hotspot and cellular backhaul for carrier infrastructure  and highspeed enterprise connectivity.  Have a look this picture.

 

What is meant by last mile?

Look at the above picture. Are you able to locate the Central Office and  the CPE such as Wifi HotSpot. The distance between these two places can be called as last mile. If you are NOT using wireless technology such as WiMAX, then you have to cover this distance by copper wire or fibre.

WiMAX is similar to wi-fi?

wi-fi is wireless and WiMAX is also wireless. But the speed and distance covered are different. Have a look at this image which compares the data rates of different wireless technologies.And, this picture also tells which technology is more suitable while you are moving.

 

 

If my laptop is having WiMAX connectivitity, what is the maximum speed I can achieve?

75mpbs. Normally one Base Station can serve for about 30 numbers of 2mbps customers or about 1000 residential customers.

Whether LINE OF SIGHT is required between the Base Station (BTS) and  Customer Premises Equipment(CPE) ?

No.

What is the normal coverage radius of a BTS?

5 to 8 km.

Our house is located 40KM away from the Base Station. Shall we get connectivity? What is the maximum speed we can achieve?

Connectivity and data rate depends on the distance of our house from the BTS. Normally maximum distance is 50KM only. The data rate also vary depending on the climatic conditions. Depending upon the noisy condition of the medium, the modulation technique also automatically changes. Have a look at this diagram. When the climate is good, the whole city gets good bandwidth(pink color). But when the climate worsens, only those very near to BTS are getting good speed.

 

 

Whether WiMAX uses licensed Spectrum or free spectrum?

Both are being used. 2 to 11 GHZ is used.

The CPE should be stationary or mobile?

For stationary CPE, the standard is 802.16-2004. The standard for mobile cpe is 802.16e